const binarySearch = (arr, item) => {
    let high = arr.length - 1
    let low = 0
    while (start < high) {
        let mid = parseInt(low+(high-low)/2)
        if (arr[mid] == item) {
            return mid
        } else if (arr[mid] > item) {
            high = mid - 1
        } else {
            low = mid + 1
        }
    }
    return -1
}